I’ve only heard the on wall M0’s and M22’s. But, Ian mentioned that they all sound very similar. The main benefit with the in wall and on/in walls is they do not protrude from the wall as much as the on walls. The on wall M22’s are pretty impressive when considering what they are and just how small the cabinet is in comparison to the book shelf versions.

I've compared my new m22s to the new onwall 22's side by side, personally I like the regular m22's a lot better. The onwalls alone sound very good, but a sub is a must. To me they sound hollow or thin compared to a full bookshelf. Even with a sub, they don't have the same presence in the mid bass and lower mid frequencies that a full speaker enclosure can give you.

I'm not trying to say they sound bad, they don't, but physics can't be cheated.

As you say SirQuack, the physics can't be cheated. While I haven't had the opportunity to demo the different 22 versions as you have, a simple browse of the specs shows the differences that cabinet volume make.

Both the in wall and on wall 22's state 70Hz-22kHz FR.The full M22 and in/on wall 22 (formerly known as the W22) have stated FR's from 60Hz - 22kHz. These two both have the larger cabinet volume.

I'm still a little suprised by the frequency specs. I had to bump up the crossover on my regular 22's to about 150hz to even get them close to the same sound on the low end. I don't have an anechoic chamber, but the 70hz seems like a stretch.

The on-wall M22s have been growing on me. I think the major differences in comparison to my bookshelf M22s are the tweeter and crossover, though. My bookshelf M22s are seven years old (wow!) so a number of improvements have been made to the design since then. Even though I know I'm losing out on some bottom end with the on-walls, I think the other improvements more than make up for it. With an EP500 in the mix to take care of that bottom end, I'm pretty satisfied with the sound.

This is a good thing, since my wife likes the aesthetics of the on-walls about 300% more than the bookshelves.

_________________________I can explain it to you but I can't understand it for you.

I agree Sirquack - my W22's do sound great, but I have a hard time in my room thinking they'll go down to 60Hz within 3dB. I have my x-over set at 80Hz which works well, but there's no way I would consider crossing at 60 Hz - I'd have a big hole in my system flatness.

I have the bookshelf M22's and am still waiting on the on-wall M22's. It sounds like a subwoofer will be in my near future, but I'm tempted to just hop over to BB or similar and get a cheepie to get by for a while, since I have some other projects going on right now and don't want to keep putting them off any longer.